Probably between 2--6 ml at 18 nic 100% VG. I'm doing MTL though so I don't go through hordes of juice. Now that I'm making my own really the idea of sub-ohming seems fine, though it's not my preferred vape. 
I seriously have some supplies (did the calculations in my head) that will last me several years after death. But you know, I'm okay with that. I (like many others) realized that yes, vaping IS about nicotine, at least for now. So, I ah, targeted that arena, though I also have 2.5 gallons of VG in my vapocalypse cupboard. Sigh. It was I need it, though I can go longer and longer between vaping, it was cheap, what can I say. I imagine if I ever run out of VG the madness will have died down and I can get it somewhere, sometime.... Though I'm not entirely sure I'll need it.... But, it sure makes my experimental disasters with mixing less painful, though. Heh. Also have much SS wire, and a huge pack of cotton and a coilbuilding set. Just gotta find a tank I love vaping where I can build my coils myself...
Your juice consumption seems fairly normal to me.
There is no "doing it right," however. It's doing it RIGHT for YOU.
Vape what's comfortable now and see how things develop (they will, most likely) 
Anna
I seriously have some supplies (did the calculations in my head) that will last me several years after death. But you know, I'm okay with that. I (like many others) realized that yes, vaping IS about nicotine, at least for now. So, I ah, targeted that arena, though I also have 2.5 gallons of VG in my vapocalypse cupboard. Sigh. It was I need it, though I can go longer and longer between vaping, it was cheap, what can I say. I imagine if I ever run out of VG the madness will have died down and I can get it somewhere, sometime.... Though I'm not entirely sure I'll need it.... But, it sure makes my experimental disasters with mixing less painful, though. Heh. Also have much SS wire, and a huge pack of cotton and a coilbuilding set. Just gotta find a tank I love vaping where I can build my coils myself...
Your juice consumption seems fairly normal to me.
Anna